Coexistence of Paget's bone disease and diffuse idiopathic skeletal hyperostosis in males

The coexistence of Paget's bone disease (PBD) and diffuse idiopathic skeletal hyperostosis (DISH) of the spine is controversial and could have implications for the pathogenic mechanisms involved in these disorders. In order to assess the prevalence of DISH in patients with Paget's disease, a prospective controlled study was carried out in which roentgenograms were obtained from a group of 50 consecutive ambulatory patients previously diagnosed as having PBD (25 males and 25 females; mean age: 66.2 +/- 8.9 years) and these were compared with 50 age- and sex-matched subjects selected randomly from various categories of medical disorders excluding PBD. DISH was found in 12 of 50 Paget's patients, this corresponding to an incidence of 24%; 10 (83%) of these 12 subjects were males. In the control population the incidence of DISH was 6%-2 males and 1 female. This difference between the two groups was statistically significant (chi 2 test; p = 0.02). Apart from the male gender, which was clearly associated with the presence of DISH in the Paget's group (p = 0.019), no other biological variable or characteristic of PBD was linked to the presence of DISH. In conclusion, our data revealed that PBD patients have a significantly greater prevalence of DISH than non-PBD probands. It would seem that the genetic mechanism which is responsible for the susceptibility of PBD to osteoclast viral infection could be related to the pathogenia of DISH in a sex-linked manner.